byaddr.c revision 193149
1/* 2 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 2000-2003 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18/* $Id: byaddr.c,v 1.39 2007/06/19 23:47:16 tbox Exp $ */ 19 20/*! \file */ 21 22#include <config.h> 23 24#include <isc/mem.h> 25#include <isc/netaddr.h> 26#include <isc/print.h> 27#include <isc/string.h> /* Required for HP/UX (and others?) */ 28#include <isc/task.h> 29#include <isc/util.h> 30 31#include <dns/byaddr.h> 32#include <dns/db.h> 33#include <dns/events.h> 34#include <dns/lookup.h> 35#include <dns/rdata.h> 36#include <dns/rdataset.h> 37#include <dns/rdatastruct.h> 38#include <dns/resolver.h> 39#include <dns/result.h> 40#include <dns/view.h> 41 42/* 43 * XXXRTH We could use a static event... 44 */ 45 46struct dns_byaddr { 47 /* Unlocked. */ 48 unsigned int magic; 49 isc_mem_t * mctx; 50 isc_mutex_t lock; 51 dns_fixedname_t name; 52 /* Locked by lock. */ 53 unsigned int options; 54 dns_lookup_t * lookup; 55 isc_task_t * task; 56 dns_byaddrevent_t * event; 57 isc_boolean_t canceled; 58}; 59 60#define BYADDR_MAGIC ISC_MAGIC('B', 'y', 'A', 'd') 61#define VALID_BYADDR(b) ISC_MAGIC_VALID(b, BYADDR_MAGIC) 62 63#define MAX_RESTARTS 16 64 65static char hex_digits[] = { 66 '0', '1', '2', '3', '4', '5', '6', '7', 67 '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' 68}; 69 70isc_result_t 71dns_byaddr_createptrname(isc_netaddr_t *address, isc_boolean_t nibble, 72 dns_name_t *name) 73{ 74 /* 75 * We dropped bitstring labels, so all lookups will use nibbles. 76 */ 77 UNUSED(nibble); 78 79 return (dns_byaddr_createptrname2(address, 80 DNS_BYADDROPT_IPV6INT, name)); 81} 82 83isc_result_t 84dns_byaddr_createptrname2(isc_netaddr_t *address, unsigned int options, 85 dns_name_t *name) 86{ 87 char textname[128]; 88 unsigned char *bytes; 89 int i; 90 char *cp; 91 isc_buffer_t buffer; 92 unsigned int len; 93 94 REQUIRE(address != NULL); 95 96 /* 97 * We create the text representation and then convert to a 98 * dns_name_t. This is not maximally efficient, but it keeps all 99 * of the knowledge of wire format in the dns_name_ routines. 100 */ 101 102 bytes = (unsigned char *)(&address->type); 103 if (address->family == AF_INET) { 104 (void)snprintf(textname, sizeof(textname), 105 "%u.%u.%u.%u.in-addr.arpa.", 106 (bytes[3] & 0xff), 107 (bytes[2] & 0xff), 108 (bytes[1] & 0xff), 109 (bytes[0] & 0xff)); 110 } else if (address->family == AF_INET6) { 111 cp = textname; 112 for (i = 15; i >= 0; i--) { 113 *cp++ = hex_digits[bytes[i] & 0x0f]; 114 *cp++ = '.'; 115 *cp++ = hex_digits[(bytes[i] >> 4) & 0x0f]; 116 *cp++ = '.'; 117 } 118 if ((options & DNS_BYADDROPT_IPV6INT) != 0) 119 strcpy(cp, "ip6.int."); 120 else 121 strcpy(cp, "ip6.arpa."); 122 } else 123 return (ISC_R_NOTIMPLEMENTED); 124 125 len = (unsigned int)strlen(textname); 126 isc_buffer_init(&buffer, textname, len); 127 isc_buffer_add(&buffer, len); 128 return (dns_name_fromtext(name, &buffer, dns_rootname, 129 ISC_FALSE, NULL)); 130} 131 132static inline isc_result_t 133copy_ptr_targets(dns_byaddr_t *byaddr, dns_rdataset_t *rdataset) { 134 isc_result_t result; 135 dns_name_t *name; 136 dns_rdata_t rdata = DNS_RDATA_INIT; 137 138 /* 139 * The caller must be holding the byaddr's lock. 140 */ 141 142 result = dns_rdataset_first(rdataset); 143 while (result == ISC_R_SUCCESS) { 144 dns_rdata_ptr_t ptr; 145 dns_rdataset_current(rdataset, &rdata); 146 result = dns_rdata_tostruct(&rdata, &ptr, NULL); 147 if (result != ISC_R_SUCCESS) 148 return (result); 149 name = isc_mem_get(byaddr->mctx, sizeof(*name)); 150 if (name == NULL) { 151 dns_rdata_freestruct(&ptr); 152 return (ISC_R_NOMEMORY); 153 } 154 dns_name_init(name, NULL); 155 result = dns_name_dup(&ptr.ptr, byaddr->mctx, name); 156 dns_rdata_freestruct(&ptr); 157 if (result != ISC_R_SUCCESS) { 158 isc_mem_put(byaddr->mctx, name, sizeof(*name)); 159 return (ISC_R_NOMEMORY); 160 } 161 ISC_LIST_APPEND(byaddr->event->names, name, link); 162 dns_rdata_reset(&rdata); 163 result = dns_rdataset_next(rdataset); 164 } 165 if (result == ISC_R_NOMORE) 166 result = ISC_R_SUCCESS; 167 168 return (result); 169} 170 171static void 172lookup_done(isc_task_t *task, isc_event_t *event) { 173 dns_byaddr_t *byaddr = event->ev_arg; 174 dns_lookupevent_t *levent; 175 isc_result_t result; 176 177 REQUIRE(event->ev_type == DNS_EVENT_LOOKUPDONE); 178 REQUIRE(VALID_BYADDR(byaddr)); 179 REQUIRE(byaddr->task == task); 180 181 UNUSED(task); 182 183 levent = (dns_lookupevent_t *)event; 184 185 if (levent->result == ISC_R_SUCCESS) { 186 result = copy_ptr_targets(byaddr, levent->rdataset); 187 byaddr->event->result = result; 188 } else 189 byaddr->event->result = levent->result; 190 isc_event_free(&event); 191 isc_task_sendanddetach(&byaddr->task, (isc_event_t **)&byaddr->event); 192} 193 194static void 195bevent_destroy(isc_event_t *event) { 196 dns_byaddrevent_t *bevent; 197 dns_name_t *name, *next_name; 198 isc_mem_t *mctx; 199 200 REQUIRE(event->ev_type == DNS_EVENT_BYADDRDONE); 201 mctx = event->ev_destroy_arg; 202 bevent = (dns_byaddrevent_t *)event; 203 204 for (name = ISC_LIST_HEAD(bevent->names); 205 name != NULL; 206 name = next_name) { 207 next_name = ISC_LIST_NEXT(name, link); 208 ISC_LIST_UNLINK(bevent->names, name, link); 209 dns_name_free(name, mctx); 210 isc_mem_put(mctx, name, sizeof(*name)); 211 } 212 isc_mem_put(mctx, event, event->ev_size); 213} 214 215isc_result_t 216dns_byaddr_create(isc_mem_t *mctx, isc_netaddr_t *address, dns_view_t *view, 217 unsigned int options, isc_task_t *task, 218 isc_taskaction_t action, void *arg, dns_byaddr_t **byaddrp) 219{ 220 isc_result_t result; 221 dns_byaddr_t *byaddr; 222 isc_event_t *ievent; 223 224 byaddr = isc_mem_get(mctx, sizeof(*byaddr)); 225 if (byaddr == NULL) 226 return (ISC_R_NOMEMORY); 227 byaddr->mctx = mctx; 228 byaddr->options = options; 229 230 byaddr->event = isc_mem_get(mctx, sizeof(*byaddr->event)); 231 if (byaddr->event == NULL) { 232 result = ISC_R_NOMEMORY; 233 goto cleanup_byaddr; 234 } 235 ISC_EVENT_INIT(byaddr->event, sizeof(*byaddr->event), 0, NULL, 236 DNS_EVENT_BYADDRDONE, action, arg, byaddr, 237 bevent_destroy, mctx); 238 byaddr->event->result = ISC_R_FAILURE; 239 ISC_LIST_INIT(byaddr->event->names); 240 241 byaddr->task = NULL; 242 isc_task_attach(task, &byaddr->task); 243 244 result = isc_mutex_init(&byaddr->lock); 245 if (result != ISC_R_SUCCESS) 246 goto cleanup_event; 247 248 dns_fixedname_init(&byaddr->name); 249 250 result = dns_byaddr_createptrname2(address, options, 251 dns_fixedname_name(&byaddr->name)); 252 if (result != ISC_R_SUCCESS) 253 goto cleanup_lock; 254 255 byaddr->lookup = NULL; 256 result = dns_lookup_create(mctx, dns_fixedname_name(&byaddr->name), 257 dns_rdatatype_ptr, view, 0, task, 258 lookup_done, byaddr, &byaddr->lookup); 259 if (result != ISC_R_SUCCESS) 260 goto cleanup_lock; 261 262 byaddr->canceled = ISC_FALSE; 263 byaddr->magic = BYADDR_MAGIC; 264 265 *byaddrp = byaddr; 266 267 return (ISC_R_SUCCESS); 268 269 cleanup_lock: 270 DESTROYLOCK(&byaddr->lock); 271 272 cleanup_event: 273 ievent = (isc_event_t *)byaddr->event; 274 isc_event_free(&ievent); 275 byaddr->event = NULL; 276 277 isc_task_detach(&byaddr->task); 278 279 cleanup_byaddr: 280 isc_mem_put(mctx, byaddr, sizeof(*byaddr)); 281 282 return (result); 283} 284 285void 286dns_byaddr_cancel(dns_byaddr_t *byaddr) { 287 REQUIRE(VALID_BYADDR(byaddr)); 288 289 LOCK(&byaddr->lock); 290 291 if (!byaddr->canceled) { 292 byaddr->canceled = ISC_TRUE; 293 if (byaddr->lookup != NULL) 294 dns_lookup_cancel(byaddr->lookup); 295 } 296 297 UNLOCK(&byaddr->lock); 298} 299 300void 301dns_byaddr_destroy(dns_byaddr_t **byaddrp) { 302 dns_byaddr_t *byaddr; 303 304 REQUIRE(byaddrp != NULL); 305 byaddr = *byaddrp; 306 REQUIRE(VALID_BYADDR(byaddr)); 307 REQUIRE(byaddr->event == NULL); 308 REQUIRE(byaddr->task == NULL); 309 dns_lookup_destroy(&byaddr->lookup); 310 311 DESTROYLOCK(&byaddr->lock); 312 byaddr->magic = 0; 313 isc_mem_put(byaddr->mctx, byaddr, sizeof(*byaddr)); 314 315 *byaddrp = NULL; 316} 317